This application relates to apparatus for controlling the liquid level in vessels and, in particular, to such apparatus for use in toilet flush tanks. The apparatus disclosed herein is an improvement of those disclosed in U.S. Pat. Nos. 6,123,099 and 6,539,973.
The aforementioned patents disclose several types of valves utilizing a flexible, resilient pinch tube as a valve member, which is controlled by an actuator engageable with the outside of the tube to pinch it closed. Some of the embodiments disclosed in those patents utilize a float which encircles and moves along an upright fill tube. Upward movement of the float with rising water level is arrested until the water level reaches the desired shutoff level, whereupon the buoyancy force on the float overrides the arresting force so that the float suddenly moves to a shutoff positioned for effecting a snap-action shutoff of the valve.
While these prior arrangements have afforded a satisfactory snap-action shutoff, they require complex floats with plural tube passages therethrough, since the outlet of the pinch valve communicates with the tank through a separate tube externally of the fill tube, which also passes through the float.